Identifying and addressing toilet leaks as soon as possible will save water as well as money. The following are a few ways that you can check for leaks in your toilet.
The easiest method is with food coloring or a dye tablet. Drop a dye tablet or a few drops of food coloring into your toilet tank. In about 15 to 20 minutes, check the toilet bowl. If there is colored water, you have a leak.
Another way is to remove the tank lid to make sure that the water level is not above the overflow pipe. If it is, you may need to replace your fill valve.
Other tell-tale signs of a leak are if you notice water trickling down the inside of the bowl without flushing or if your toilet is constantly making a noise like it is running. If you can get the running noise to stop by jiggling the handle, you may need to adjust or replace the flapper or the chain that connects it to the flush handle.
If none of these tests help you determine if you have a leak, there is one more test that you can perform. Turn off the water to the toilet when you go to bed. Check how much water is in the tank the next the following morning. Less than an inch of water in the tank is a good indication that you have a leak and should replace one or more of the parts in your tank.